Devices for Vascular Occlusion

ABSTRACT

An occlusive device, occlusive device delivery system, method of using, and method of delivering an occlusive device, and method of making an occlusive device to treat various intravascular conditions is described.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 62/293,710 filed Feb. 10, 2016 entitled Devices for VascularOcclusion, which is hereby incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

Vessel occlusion is often necessary in a variety of cases—including butnot limited to treatment of aneurysms, atrial septal defects, patentforamen ovale, left atrial appendage occlusion, patent ductusarteriosus, fistula, arterio-venous malformations, fallopian tubeocclusion for the purposes of sterilization, and occlusion in theperipheral vasculature. One method of vessel occlusion involves fillingthe vessel or malformation or aneurysm with occlusive devices for thepurposes of embolization. Typically, embolic coils are used for thispurpose.

Successful occlusion can be difficult due to the complex geometriespotentially associated with the various target areas of the vasculature.An occlusive device which can conform to the complex shapes associatedwith the vasculature, and which can quickly occlude a target area istherefore desirable.

SUMMARY OF THE INVENTION

An occlusive device is described.

In one embodiment, the occlusive device comprises a retention portionand a holding portion. In one embodiment, the retention portion isclover-shaped and the distal holding portion is a cylindrical mesh.

In one embodiment, the occlusive device comprises a retention portionand holding portion, where another occluding device can be used to fillthe holding portion.

In one embodiment, the occlusive device comprises a retention portionand holding portion and an attached delivery tube through whichadditional occluding devices can be delivered to fill the holdingportion.

In one embodiment, the occlusive device comprises one or more discshaped elements.

In one embodiment, the occlusive device comprises one or more discshaped elements and a central element traversing through at least someof the disc shaped elements.

In one embodiment, the occlusive device comprises a ribbon-shape. In oneembodiment, the occlusive device comprises a spiral-ribbon shape.

In one embodiment, the occlusive device comprises smaller and largerdiameter regions. In one embodiment these smaller and larger diameterregions are sequential with a smaller diameter region alternating with alarger diameter region. In one embodiment, the smaller diameter regionsutilize one substantially consistent shape and the larger diameterregions utilize another substantially consistent shape.

In one embodiment, a delivery system for delivering and detaching anocclusive device is described.

In one embodiment, an occlusive device utilizes a stretch resistantmember to help control expansion of the occlusive device upon delivery.

In one embodiment, an occlusive device comprises an outer member and aninner member. In one embodiment, the inner and outer members arecomprised of the same braided material, just packed into each other.

In one embodiment, an occlusive device comprises one or more sealingmembers, where the sealing members can be located on at least one of theproximal and/or distal ends of the device.

In another embodiment, an occlusive device comprises a structuralportion, and a mesh or membrane portion over the structural portion.

In another embodiment, an occlusive device comprises a neck bridgeelement and one or more filling structures.

In another embodiment, an occlusive device comprises a neck bridgeelement and an embolic material, such as embolic coils.

In another embodiment, an occlusive device comprises structural strutsand a distal contact portion.

In another embodiment, an occlusive device comprises two separateocclusive sections connected by a coil.

A method of manufacturing an occlusive device is described.

In one embodiment, an occlusive device is manufactured by taking acenter element and attaching one or more wires to this center element tocreate a retention portion. In one embodiment, an occlusive device ismanufactured by taking a center element and passing one or more wiresthrough this center element to create a retention portion. In oneembodiment, the shape of this retention portion is clover-like. Aholding portion, in one embodiment a mesh comprising wires, can then beattached to the retention portion.

In one embodiment, an occlusive device is manufactured by winding theocclusive device over one of more disc-shaped elements. The one or moredisc shaped elements have a plurality of holes passing through which theconstituent wires making up the occlusive device are wound through. Theone or more disc shaped elements may optionally contain a center channelwhich the wires are pulled through in order to create a center elementtraversing through at least some of the disc-shaped elements.

In another embodiment, an occlusive device is manufactured byheat-setting the device over a mandrel with a shape comprising smallerand larger-diameter regions. In another embodiment, an occlusive deviceis manufactured over a mandrel with a relatively consistent diameter.Marker bands or tie elements are then selectively placed throughout theocclusive device to create smaller diameter regions throughout thelength of the occlusive device.

In another embodiment, a braider utilizes both an inner and an outerbraider to braid an occlusive device. The occlusive device may be woundover more than one mandrel, where the use of both and inner and outerbraider can help speed up the manufacturing process.

In another embodiment, a tapered mandrel can be used with a braider tocreate an occlusive device comprising both an inner and an outer region.

In another embodiment, a removable mandrel can be used to wind anocclusive device.

In another embodiment, a vertical braider is described. The verticalbraider may be used to manufacture an occlusive device.

In another embodiment, an implant comprising a closed end is braidedover a mandrel utilizing a closed end and a series of pins on the closedend section to help create the closed end. The implant may be anocclusive device.

In another embodiment, a rotational braider is described. The rotationalbraider may be used to create an implant with regions of varyingstiffness.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of which embodiments ofthe invention are capable of will be apparent and elucidated from thefollowing description of embodiments of the present invention, referencebeing made to the accompanying drawings, in which:

FIG. 1 illustrates an occlusive device comprising a retention portionand a holding portion.

FIG. 2 illustrates an occlusive device comprising a retention portionand a holding portion.

FIG. 3 illustrates an occlusive device comprising a retention portionand a holding portion.

FIG. 4A illustrates an occlusive device comprising a retention portionand a holding portion.

FIG. 4B illustrates an occlusive device comprising a retention portionand a holding portion.

FIG. 4C illustrates an occlusive device comprising a retention portionand a holding portion.

FIG. 5 illustrates an occlusive device comprising a retention portionand a holding portion.

FIG. 6 illustrates an occlusive device, comprising multiple retentionportions.

FIG. 7 illustrates a manufacturing element used to create a retentionportion of an occlusive device.

FIG. 8 illustrates an occlusive device comprising multiple disc-shapedportions and a mandrel for making the same.

FIG. 9 illustrates an occlusive device comprising multiple disc-shapedportions and a mandrel for making the same.

FIG. 10 illustrates an occlusive device comprising multiple disc-shapedportions and a mandrel for making the same.

FIG. 11 illustrates an occlusive device comprising multiple disc-shapedportions and a mandrel for making the same.

FIG. 12 illustrates an occlusive device comprising multiple disc-shapedportions and a mandrel for making the same.

FIG. 13A illustrates an occlusive device, comprising smaller and largerdiameter regions.

FIG. 13B illustrates an occlusive device, comprising smaller and largerdiameter regions.

FIG. 14 illustrates an occlusive device, comprising smaller and largerdiameter regions.

FIG. 15 illustrates an occlusive device comprising a spiral ribbon.

FIG. 16 illustrates a detachment system for an implant, where theimplant can be an occlusive device.

FIG. 17 illustrates a detachment system for an implant, where theimplant can be an occlusive device.

FIG. 18 illustrates a detachment system for an implant, where theimplant can be an occlusive device.

FIG. 19 illustrates a detachment system for an implant, where theimplant can be an occlusive device.

FIG. 20 illustrates a detachment system for an implant, where theimplant can be an occlusive device.

FIG. 21 illustrates a detachment system for an implant, where theimplant can be an occlusive device.

FIG. 22 illustrates a detachment system for an implant, where theimplant can be an occlusive device.

FIG. 23A illustrates an occlusive device having a tensioning member thatallows the device to expand in a curved configuration.

FIG. 23B illustrates an occlusive device having a tensioning member thatallows the device to expand in a curved configuration.

FIG. 24A illustrates an occlusive device that expands in an offsetconfiguration from its catheter.

FIG. 24B illustrates an occlusive device that expands in an offsetconfiguration from its catheter.

FIG. 24C illustrates a mandrel for creating the occlusive device ofFIGS. 24A and 24B.

FIG. 25A illustrates a braided occlusive device with recessed endtermination points and a mandrel for making the same.

FIG. 25B illustrates a braided occlusive device with recessed endtermination points and a mandrel for making the same.

FIG. 25C illustrates a braided occlusive device with recessed endtermination points and a mandrel for making the same.

FIG. 25D illustrates a braided occlusive device with recessed endtermination points and a mandrel for making the same.

FIG. 26A illustrates an occlusive device comprising an outer and innersection.

FIG. 26B illustrates an occlusive device comprising an outer and innersection.

FIG. 26C illustrates an occlusive device comprising an outer and innersection.

FIG. 26D illustrates an occlusive device comprising an outer and innersection.

FIG. 26E illustrates an occlusive device comprising an outer and innersection.

FIG. 26F illustrates an occlusive device comprising an outer and innersection.

FIG. 27A illustrates an occlusive device comprising a sealing member.

FIG. 27B illustrates an occlusive device comprising a sealing member.

FIG. 27C illustrates an occlusive device comprising a sealing member.

FIG. 27D illustrates an occlusive device comprising a sealing member.

FIG. 27E illustrates an occlusive device comprising a structural portionand a mesh or membrane portion.

FIG. 27F illustrates an occlusive device comprising a structural portionand a mesh or membrane portion.

FIG. 28A illustrates a braider comprising an inner and an outer braider.The braider can be used to braid an occlusive device.

FIG. 28B illustrates a braider comprising an inner and an outer braider.The braider can be used to braid an occlusive device.

FIG. 28C illustrates a braider comprising an inner and an outer braider.The braider can be used to braid an occlusive device.

FIG. 29A illustrates a tapered mandrel used to create an occlusivedevice.

FIG. 29B illustrates a tapered mandrel used to create an occlusivedevice.

FIG. 29C illustrates a tapered mandrel used to create an occlusivedevice.

FIG. 29D illustrates a tapered mandrel used to create an occlusivedevice.

FIG. 29E illustrates a tapered mandrel used to create an occlusivedevice.

FIG. 30 illustrates a vertical braider.

FIG. 31A illustrates a mandrel used to create an implant with closedends.

FIG. 31B illustrates a mandrel used to create an implant with closedends.

FIG. 31C illustrates alternate embodiments of an occlusive device with abraided, closed end.

FIG. 31D illustrates alternate embodiments of an occlusive device with abraided, closed end.

FIG. 32A illustrates cross sections of a braid created by a rotationalbraider.

FIG. 32B illustrates cross sections of a braid created by a rotationalbraider.

FIG. 32C illustrates cross sections of a braid created by a rotationalbraider.

FIG. 33A illustrates a detachment system used with an occlusive device.

FIG. 33B illustrates a detachment system used with an occlusive device.

FIG. 33C illustrates a detachment system used with an occlusive device.

FIG. 33D illustrates a detachment system used with an occlusive device.

FIG. 33E illustrates a detachment system used with an occlusive device.

FIG. 34A illustrates a detachment system used with an occlusive device.

FIG. 34B illustrates a detachment system used with an occlusive device.

FIG. 35 illustrates an occlusive device comprising a neck bridgeelement.

FIG. 36 illustrates an occlusive device comprising a neck bridgeelement.

FIG. 37 illustrates an occlusive device comprising a neck bridgeelement.

FIG. 38 illustrates an occlusive device comprising a neck bridgeelement.

FIG. 39 illustrates an occlusive device comprising a neck bridgeelement.

FIG. 40 illustrates an occlusive device comprising a neck bridgeelement.

FIG. 41 illustrates an occlusive device comprising struts and a distalcontact portion.

FIG. 42 illustrates an occlusive device comprising struts and a distalcontact portion.

FIG. 43 illustrates an occlusive device comprising a top element, bottomelement, and coil connecting component.

FIG. 44 illustrates an occlusive device comprising a top element, bottomelement, and coil connecting component.

FIG. 45 illustrates an occlusive device comprising a top element, bottomelement, and coil connecting component.

DESCRIPTION OF EMBODIMENTS

Specific embodiments of the invention will now be described withreference to the accompanying drawings. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein; rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art. Theterminology used in the detailed description of the embodimentsillustrated in the accompanying drawings is not intended to be limitingof the invention. In the drawings, like numbers refer to like elements.

An occlusive and/or embolic device is described; the device may be usedfor a variety of purposes including—but not limited to—fillinganeurysms, atrial septal defects, patent foramen ovale, left atrialappendage occlusion, patent ductus arteriosus, fistula, arterio-venousmalformations, fallopian tube occlusion for the purposes ofsterilization, and occlusion in the peripheral vasculature. Some of theembodiments described herein can be considered as intrasaccular devices.

For the purposes of illustrating the use of the embodiments describedherein, treatment of aneurysms may be described for ease of illustrationand consistency. However, the various embodiments of the device can beused for a number of purposes, including those described above, inaddition to treating aneurysms.

Typical technologies to treat vascular conditions, such as aneurysms,utilize coils to fill the space or clips to cut off blood flow to thetarget areas. These technologies may have difficulty if theaneurysm/treatment area has a wide neck or complex shape, sinceplacement and retention of the coils may be problematic. Intrasacculardevices aim to create a blockage at the neck of the aneurysm and toconform to the general shape of the aneurysm, thereby restricting bloodflow from the neck into the aneurysm to occlude the target site.Examples of such devices can be found in commonly assignedUS20140200607, which is hereby incorporated by reference in itsentirety.

The intrasaccular devices described herein may also be combined withembolic coils, liquid embolic, or other embolic agents to augment theocclusive effect at the target site. Many of the embodiments disclosedin this specification are directed to a detachable intrasaccular deviceconnected to a catheter that also allows embolic material to bedelivered through its catheter. The catheter includes a passageextending along its length and opening within the intrasaccular device.Once the intrasaccular device is advanced to the target aneurysm andexpanded, embolic agents, such as embolic coils or liquid embolicmaterial, can be advanced through the catheter and out into theintrasaccular device and/or into the aneurysm. Finally, theintrasaccular device can be detached from the catheter. In this respect,the intrasaccular device can be deployed in an aneurysm first to blockit off from the adjacent blood vessel, and the embolic agents can besubsequently delivered. This order of a treatment procedure may resultin the embolic agents being better retained in the aneurysm versusdelivering embolic agents first and then an intrasaccular device second.The aperture in the intrasaccular device can also or alternately be usedto attach a tether or monofilament that is also connected to thecatheter, allows for a detaching the intrasaccular device via adetachment mechanism within the catheter.

One embodiment of such an intrasaccular device 11 can be seen in FIGS.1-5 The intrasaccular device 11, comprises a holding portion 12 forsupporting a plurality of embolic coils 6, and a retention portion 10that expands and supports a proximal end of the holding portion 12. Asdescribed in further detail below, the intrasaccular device 11 alsoincludes an aperture connected to a passage in the microcatheter 9,which allows for the delivery of embolic agents after expansion and/orthe connection of a tether to detachably retain the intrasaccular device11.

The holding portion 12 is, in one example, composed of a plurality ofwires woven into a mesh or braid, and further expands to a cylindricalor concave dish shape. As seen best in FIGS. 4A and 4B, the proximal endof the holding portion 12 terminates its mesh with a cylindricalproximal end member 15. This end member 15 preferably includes a passage15A (see FIG. 4B) that connects between the proximal and distal sides ofthe holding portion 12.

In one example, the proximal end member 15 can be created by firstgathering the proximal end of the mesh of the holding portion 12 andplacing a relatively larger radiopaque marker band around it. A second,smaller marker band is lined up on the inside of the mesh andconcentrically aligned with the larger marker band. Finally, the twomarker bands are welded together. Since both marker bands are annular orring-shaped, they create a proximal end member 15 with the passage 15Atherethrough.

In another example, the proximal end member 15 can be created by feedingall of the braided wires of the holding portion's mesh through a middleof a radiopaque marker band. A mandrel with a poor welding ability(i.e., that tends not to melt at normal welding temperatures) is placedwithin the mesh and marker band, and the mesh and ring are welded,leaving the passage 15A through the resulting proximal end member 15.

In yet another example, the proximal end member 15 can be created byplacing the braided wires of the holding portions mesh into and througha tube having poor welding characteristics. A mandrel, also having poorwelding characteristics, is passed through the inside of the mesh,allowing the wires of the mesh to be welded together. The tube andmandrel are removed from the mesh, leaving the passage 15A through theresulting proximal end member 15. Optionally, an additional weld can beperformed around the outside diameter of the device to increase thestrength of the end member 15.

In another embodiment, the size of the proximal end member 15 can bereduced by first cutting a proximal end of initial braid of the holdingportion 12 into pointed or triangular flaps 12A. For example, between 4and 16 flaps can be created. The resulting flaps 12A can be broughttogether to form the proximal end member 15 in one of theabove-mentioned techniques, resulting in an end member 15 that issubstantially smaller than without creating the flaps 12A, due to adecrease in the number of wires being held together at the end member15.

The retention portion 10, in one example, includes a plurality of loops22 formed from one or more wires, and radially expands such that theloops 22 are substantially aligned in a single plane. The retentionportion 10 includes a center element 18, shown in the top and side viewsof FIGS. 3 and 4, that retains the wires forming the loops 22. Thecenter element includes a center aperture or lumen 21 and a plurality ofsmaller apertures 20. The center aperture 21 is preferably connected oraligned with the passage 15A of the holding portion 12, thereby creatinga continuous passage between a passage in catheter 9, the passage 15A,and the aperture 21. This continuous passage allows embolic agents to beadvance out into the intrasaccular device 11.

A plurality of wires pass through the plurality of smaller apertures 20to create a clover-like shape as shown in FIG. 5. Though four of these“clover leaf” loops 22 are shown in FIG. 5, fewer or more leafs can beused. In one example, each leaf can be formed from a single wire and oneend of the wire is placed through a first hole, the other end of thewire is placed through the second hole. The two ends of the wire arewelded or otherwise joined together. Thus, each leaf utilizes two of theholes on center element 18. In FIGS. 3-4, eight holes are shown whichare respectively used with four leaves. In another example, the centerelement would include no holes, instead it is just a piece which theclover leaf wires are affixed to (via adhesive, mechanical ties, orwelding).

FIG. 7 shows a mandrel or fixture 17 that can be used to create theretention portion 10. The fixture 17 includes a slot 17A to accommodatecenter element 18. Wires can be wound around the ‘petal’ shaped fixtures17B to create the “clover-leaf” loops 22, a press 17C may optionally beused to press down on the device and hold the shape and a subsequentheat treating procedure can optionally be used as well.

The holding element 12 can be affixed to retention portion 10 viaadhesive, mechanical ties, or welding. The holding element 12 ispositioned across the proximal-facing part of the “clover leaf” loops 22and then extends like a cylinder with walls projecting distally. Thoughthe holding element 12 as shown in FIG. 1 has an open top, a closed topmay be used. The holding element 12 can be comprised of a braid or meshof wires, such as nitinol wires. Radiopaque material such as tantalum,platinum, gold, and/or palladium may also be used. In one example, themesh solely comprises nitinol wires. In another example, the meshcomprises nitinol wires along with another radiopaque wire (such as thematerials described above). In another example, wires comprising aradiopaque core and nitinol exterior or a nitinol core and a radiopaqueexterior may be used. The retention portion 10, in one example, ispositioned at the neck of the aneurysm while the holding element 12 islocated in the interior of the aneurysm 14 in order to fill it, as bestseen in FIG. 2.

The device 11 of FIG. 1 can be located within a larger delivery catheter8, in which the device 11 itself is connected to a smaller microcatheter9, which can either be tracked through the larger catheter 8 or ispre-placed within a distal part of the delivery catheter 8. The proximalend of the holding portion 12 of the device 11 can either sit flush withthe center element 18 of retention portion 10, extend proximally pastretention portion 10, or end roughly flush with either the back or thefront of the “clover leaf” loops 22. In another example, the wireportions of the clover leaf loops 22 are located under the centerelement 18, since they pass through the apertures 20 of the centerelement 18 (see FIG. 3). This creates a type of basket (in the shape ofFIG. 5, four loops would produce four wire basket protrusions), and theproximal end of mesh holding portion 12 would be located within thisbasket and be bound by the wires of this basket. Alternatively, thewires of the holding portion 12 can be directly affixed above orunderneath the clover leaf loops 22 via adhesive, mechanical ties, orwelding. If this technique is used, the mesh should be configured so asto not obstruct the center aperture 21 of center element 18. As will beexplained later, this lumen can be used to deliver additional embolicagents and thus the lumen should be unobstructed.

In one embodiment, the occlusive device 11 of FIG. 1 is attached to amicrocatheter 9, that is, the microcatheter 9 is connected to the centerelement 18, holding portion 12, and retention portion 10 at the distalend of the microcatheter 9. This microcatheter 9 is delivered through alarger catheter 8, and the holding portion 12 and retention portion 10assume a collapsed configuration when within this larger catheter 8. Inthis collapsed configuration, the retention portion clover leaf loops 22are pushed together (akin to a flower bud before blossoming) and arelocated past the distal end of the microcatheter, where the holdingportion is located further distally, also in a collapsed configuration.The larger delivery catheter 8 is either retracted to expose themicrocatheter 9 and the attached occlusive device 11, or themicrocatheter 9 is pushed out of the distal end of the delivery catheter8 to expose the device. Upon exposure, the holding and retention portionassume their expanded configuration as shown in FIG. 1. The lumen of themicrocatheter 9, after placement of the occlusive device 11 within thetarget treatment site 14, then can be used to deliver additional embolicagents such as embolic coils 6 or liquid embolic material, as best seenin FIG. 2.

Another embodiment may solely use the retention portion 10 and noholding portion 12. In such an embodiment, the retention portion wouldbe used solely to prevent subsequently delivered embolic coils fromfalling out of the neck of the aneurysm 14. Another embodiment mayutilize a retention portion 10 with a mesh layer lying either above,under, or completely surrounding both sides of the “clover leaf” loops22 of the retention portion 10. The mesh provides an occlusive effect tolimit the amount of blood flow coming into the aneurysm (that is, themesh itself provides a barrier to blood entry). Any optionalsubsequently introduced embolic agents such as embolic coils or liquidembolic would then augment the occlusion within the aneurysm/treatmentsite.

After the occlusive device 11 is placed at the target treatment site andany optional embolic materials (i.e. coils, liquid embolic, or otherembolic agents) are introduced through the microcatheter 9, theocclusive device 11 is detached from the microcatheter to remain at thetreatment site, allowing the microcatheter 9 to be withdrawn.

A detachment system can be utilized with center element 18 of retentionelement 10. Detachable tip devices are known in the art in order todetach a distal section of a microcatheter, and are often used withliquid embolic delivery systems so that if a distal section of thecatheter is stuck or “glued” to the delivered liquid embolic, it can bedetached so the rest of the catheter can be withdrawn. A detachable tipcan be utilized with center element 18, thus the microcatheter wouldhave center element 16 and retention element 10 built onto the distaltip of said microcatheter. An electrolytic, thermal, or mechanicaldetachment system can be used to sever the center element from themicrocatheter and leave the occlusive device at the target treatmentsite. Alternatively, the detachment junction may be located proximal tothe center element, for example the detachable tip element may beconnected to center element 16, but placed proximally of said centerelement. U.S. Pub. 2015/0137773 discloses several detachable tip systemembodiments which may be utilized with this embodiment, and is herebyincorporated by reference in its entirety.

FIGS. 33A-33E illustrate a unique detachment system 107 that can be usedwith the occlusive device 11 shown in FIG. 1, as well as any of theother occlusive devices described in this specification. Unlike otherprior art detachment systems, the embodiment of FIGS. 33A-33E show adetachment system able to accommodate the center aperture or lumen 21(best seen in FIG. 3). One of the embodiments of this device 107utilized the occlusive device 11 connected to the distal end of asmaller microcatheter or delivery tube 106, where the device 107 itselfis delivered through another larger catheter. The detachment system 107allows the microcatheter or delivery tube 106 connected to the occlusivedevice 11 to detach from the occlusive device 11 at an appropriate time.For example, the occlusive device 11 is placed in an aneurysm, theattached microcatheter 106 would be used to deliver additional embolicagents (such as liquid embolic or coils), and then the microcatheter 106is detached and removed, leaving the occlusive device 11 in place. Thedetachment system 107 utilizes a heater 104 in the distal region ofattached microcatheter 106. Heater 104 can be a resistive wire coil or alaser cut sheet of various patterns (e.g., the square wave pattern shownin the figures). Wires 108 a and 108 b connect in two locations to theheater 104 supplied by a voltage source at the proximal end of thedevice 107 so each wire is oppositely polarized, allowing the heater 104to convey a current. Cylindrical cover 110 sits over the heater 104, andthere can be a sacrificial polymer layer or adhesive layer between cover110 and heater 104. The operating principal is that the heat generatedby the heater 104 will sever the sacrificial layer and detachmicrocatheter 106 from cover 110, leaving the microcatheter free toretract from the vasculature, as shown in FIGS. 33D and 33E.

In FIG. 33A, both the sacrificial polymer or adhesive layer and theheater are shown as extending more than 180 degrees but less than 360degrees around the aperture or lumen. Various configurations arepossible. For instance, the sacrificial inner polymer or adhesive layerwhich is melted by the heater may extend in selective, non-continuoussegments around the periphery of the aperture. The heater andsacrificial layer can extend a full 360 degrees or close to 360 degreesaround the aperture. One of the heater or sacrificial layer can extend afull 360 degrees around the aperture while the other element extendsless than 360 degrees around the aperture. It is preferable that thesacrificial layer extends at least 180 degrees around the aperture,while the heater should at least cover the breadth of the sacrificiallayer.

A method of operation utilizing the occlusive device 11 of FIG. 1 anddetachment system 107 of FIGS. 33A-33E involves having an occlusivedevice 11 with attached microcatheter 106 and delivering this systemthrough a larger catheter. When the occlusive device 11 is appropriatelyplaced, additional embolic agents may optionally be delivered throughattached microcatheter 106, then the detachment sequence is initiated todetach microcatheter 106 from the occlusive device 11, and themicrocatheter 106 is subsequently withdrawn.

FIGS. 34A and 34B illustrate another embodiment of an occlusive devicedetachment system 150 that can be used with the occlusive device 11, aswell as any of the other occlusive devices described in thisspecification. As seen in FIG. 34B, the system 150 uses two tethers 159that are attached to a device coupling ring 152 on the proximal end ofan occlusive device and to the tubular pusher body 156. Each tether 158is surrounded by a heater coil 158 that are connected to a selectivelyactivated power supply which, when activated, increase in temperatureand break the tether 159, releasing the device coupling ring 152 and theocclusive device it is connected to.

The heater coils 158 are preferably located within two oppositelypositioned channels cut into the tubular pusher body 156. The passagewithin the heater coils 158 are each aligned with apertures 154A througha pusher coupling ring 154. Similarly, the device coupling ring 152includes two apertures 152A that are oppositely or diametricallypositioned from each other and that can be aligned with the apertures154A. The tether 159 is tied or fixed on the distal side of theapertures 152A, passing through the apertures 152A, through theapertures 154A, through the heater coil 158, and tied/fixed proximallyof the heat coil 158 and within the slot 156A.

If the occlusive device includes a braid or mesh, similar to the device11, it is attached to the device coupling ring 152 by first feeding themesh through the main opening of the ring 152 and then placing an innermandrel matching the size of the central lumen of the pusher tube 156within the middle of the captured mesh. The end of the mesh is thenwelded to the ring 152 and the mandrel is removed, leaving a passage inthe occlusive device. Since the main opening of the pusher coupling ring154 is sized and positioned over an end of the pusher tube 156, thecentral lumen of the pusher tube 156 aligns with the passage created bythe device coupling ring 152 and mesh of the occlusive device. Thisallows embolic agents to be advanced through the central pusher lumenand through the occlusive device, prior to the occlusive device beingdetached.

Multiple retention portions 10 can be used, as shown in FIG. 6. Themore-proximal retention portion 13 b is placed at the neck of theaneurysm and the distal retention portion 13 a is placed further withinthe aneurysm. This embodiment may also be used with the holding element12 of FIG. 1, in which the distal retention portion 10 b is located atthe distal end of the holding element 12. The detachment occurs at theretention portion 13 b using the heating techniques described above.

FIGS. 8-12 relate to several embodiments of an occlusive device composedof a braid forming multiple disc shaped sections 31, such as the device30 a of FIG. 9 having four disc shapes. Though the term ‘disc-shaped’ isused, the shaped sections may take on a number of shapes includingellipsoid, ovular, cylindrical, conical, frusto-conical, etc. Thepurpose of such a shape is to allow for both compressibility andelongation of the occlusive device.

This shape is created via a plurality of winding mandrels 26 that havethe shape of desired braided section 31. FIG. 8 illustrates one exampleof two disc-shaped mandrels 26 connected together by a post 24 extendingthere through. Each mandrel 26 includes a plurality of holes 28 thatpins 23 can be inserted into to form a desired braiding pattern. Aportion of the pin 23 sits outside the hole 29 and the braid can bewound around the various pins to create the occlusive device shape. Eachmandrel 26 can have the same shape, each mandrel 26 can have a differentshape, or a combination or similar/different shapes can be used for aplurality of mandrels 26.

FIG. 10 shows an occlusive device embodiment 33 similar to device 30 aof FIG. 9, but with a center braid element 32. The shaped mandrels 26 ofFIG. 8 include a center post 24. When the wires are wound through thetop mandrel to create the top part of the occlusive device, theremaining wires can be pulled through the center element and through thebottom of the center post 24. Alternatively, if the center element 24 isa rod and has no lumen, the remaining wires are pulled around and notthrough the center element 24. Alternatively, the constituent wires arefirst pulled through/around the center rod 24 and then the mandrelwinding commences. Various winding techniques are possible. For example,if there are three disc shaped elements 31 used, as shown in FIG. 10,the process may start with winding around the middle mandrel 26, thenthe bottom mandrel 26, then pulling the wires up back over the mandrels,and the wires are then wound over the top mandrel 26—this would create amultiple-layered effect where the side walls would be doubled up over aportion of the mesh device since wires are pulled back over the device.FIGS. 9-12 show the occlusive device comprising 3-4 shaped sections 31,however, fewer or more shaped sections 31 can be used.

Other occlusive device shapes may utilize the center element throughonly a portion, but not all, of the braid. Various occlusive shapes arepossible, utilizing fewer or more disc shaped elements. FIG. 11 showsanother occlusive device 35 shape utilizing various elements 31 ofdifferent shapes and a center element through only a portion of theocclusive device. In one example, the proximal ends of the wires may bewelded or attached to the proximal ends of the center element 32 so thatthe proximal end of the occlusive device is integral.

FIG. 12 shows the device 33 of FIG. 10 within an aneurysm 14. Asmentioned previously, one advantage of utilizing a mesh and havingdifferent disc-shaped elements is compressibility and elongation of thebraid. The braid can elongate and lessen the radial dimension of thedisc elements, or compress and expand radially by sacrificinglongitudinal elongation.

In one embodiment, a winding method of winding an occlusive device ofFIGS. 8-12 is described and shown in FIGS. 28A-28E. The winding methodis useful to create a device similar to those shown in FIGS. 10-12,which utilize a center braid element 32 within the disc portions 31. Thewinding process utilizes two braiding mechanisms—an outer braider 84 andan inner braider 86. A first set of wires 80 is connected to outerbraider 84 and these wires 80 are wound over the pins of the mandrel26A. A second set of wires 82 is connected to the inner braider 86 andthese wires are not braided over the pins but are instead pulled intothe center channel of the mandrel (i.e. element 24 of FIG. 8). Wires 82are then placed onto the outer braider 84.

A second mandrel 26B is placed next to the first mandrel 26A. The firstset of wires 80 are pulled through the inner channel of the secondmandrel 26 b (similar to how wires 82 were initially pulled through theinner channel of the first mandrel 26 a), while the second set of wires82 are wound over the pins of the second mandrel. The first set of wires80 are connected to the inner braider. As can be appreciated, whenever aset of wires is pulled through the inner channel of the mandrel, saidwires are connected to the inner braider—while when the set of wires iswound over the pins of the mandrel, said wires are connected to theouter braider. The braiders have a number of carriers 86 and thecarriers contain a number of bobbins to accommodate the wires, thebraider can be automated so that the carriers rotate in variousconfigurations while the mandrel moves longitudinally to enable thebraiding to occur. Additional mandrels can also be placed and the wirearrangement would continue to alternate, so, for example, the first setof wires 80 would first form the outer braid around the first mandrel,then the inner braid in the second mandrel, then the outer braid of thethird mandrel—while the second set of wires 82 would form the innerbraid of the first mandrel, then the outer braid of the second mandrel,then the inner braid of the third mandrel, etc. Thus, the inner braid 32of this winding method described can be thought of as discontinuoussince different wire elements are forming different portions of theinner braid, while different wire elements also form different portionsof the outer braid. The outer braid would need more carriers to hold thevarious wires since at some point all the wires (both wire sets 80, 82)will be held by the outer braider—while the inner braid would only holdeither wire set 80, 82, or neither—thus the outer braider 84 would needat least twice as many carriers as inner braider 86. For example, if thebraids for each section were comprised of 48 wires (i.e. each wire set80 and 82 comprise 48 wires for a total of 96 wires used), the innerbraider should have at least 48 carriers to accommodate one of the sets,while the outer braider should have at least 96 carriers to accommodateboth sets of wires.

FIGS. 28A-28C show the various manufacturing steps just described.Different winding methods may also utilize a continuous inner element32, for example second set of wires 82 would be pulled through the innerchannel of a series of mandrels, while first set of wires 80 is woundaround the periphery of the various mandrels. If an inner and outerbraider were to be used with such a configuration, the second set ofwires 82—which comprises the continuous inner element 32—would remainconnected to the inner braider; meanwhile the first set of wires80—which comprises the outer braided portion—would remain connected tothe outer braider during the braiding operation.

FIGS. 29A-29E show another method of creating a braid with multiplelayers. A tapered mandrel 88 is braided by braider 90. The taper allowsone end to have a smaller diameter, one end to have a larger diameter,and varying diameter in between the ends. It is desirable that a portionof the smaller diameter end 88 a has a consistent diameter, as shown inFIG. 29C, for reasons that soon will become apparent. The taperedmandrel is braided. A circular element 92 can be placed in one or morelocations along the smaller, consistent diameter portion 88 a of thetapered mandrel. The rest of the braid is then folded back over thecircular element, which creates the outer globular shapes, while portion88 a remains and comprises the inner braid portion. In FIG. 29E, threecircular elements are placed along section 88 a in order to create threeenlarged sections. The folded sections can be tied and heat set to setthe shape.

FIGS. 13A and 13B shows an occlusive device 37 comprising a tubularbraid that is flattened into a dual layer and then heat shaped to createa series of smaller width mesh regions 39 and larger width regions 30 b(i.e. a plurality of “petal” shapes 30 b). These petal shapes 30 b canbe heat set a second time to impart a curve shape that roughly matchesthe curve within an aneurysm.

If the starting tubular braid was woven with a uniform braid pattern,the braid density would be the greatest in the smaller width regions 39and least dense in the middle of each petal 30 b. However, since themiddle of the petal 30 b is the location in which the device 37 attemptsto create the largest flow disruption within the aneurysm, such braiddensity may not optimally disrupt flow as intended. FIG. 14 illustratesa braid technique and pattern that varies both the pitch and width ofthe braid to provide an increased braid density area 41 in the middle ofthe petal 30 b and a decreased braid density area 43 between the centerof the petals 30 b. This variable pitch/widths technique allows thebraid density to be optimized for the greatest flow disruption at thelarger widths of the petal where it is needed most.

A braid fixture 35A can be used to create the variable pitch/width ofthe braid. The fixture 35A is a bulb structure that regularly increasesand decreases in diameter, forming a repeating, three-dimensional wavepattern. The fixture 35A also includes a plurality of mounting locationsfor pins 35B that are located at regular intervals around the fixture35A that allow one or more wires to be braided around the fixture 35A.The longitudinal distance between each pin 35B is smallest at the peakof each of the “waves” in area 41 and gradually increases as the troughof the wave is reached in area 43, after which, the spacing increasesagain as it approaches the wave peak. In this regard, the pore size ofthe braid pattern is the smallest at the peak of each “wave” and thelargest at the trough of a “wave”.

FIG. 15 shows an occlusive device 34 comprising a spiral ribbon mesh.The spiral ribbon may either have a uniform or variablediameter/thickness. The holding element 12 of FIG. 1, and occlusivedevices of FIGS. 9-15 utilize a mesh or braid of wires. The wires can bemade of nitinol, cobalt-chromium, polymer, stainless steel, and/orspring-tempered stainless steel. Radiopaque material such as tantalum,platinum, gold, and/or palladium may also be used instead, or may beincorporated into the mesh along with the non-radiopaque materialslisted in the previous sentence. In one example, the mesh may solelycomprise nitinol wires, in another example it may comprise a mesh ofnitinol wires along with another radiopaque wire (such as the materialsdescribed above) comprising the mesh. In another example, wirescomprising a radiopaque core and nitinol exterior or a nitinol core anda radiopaque exterior may be used. In one example, the wire diameterscan be about 0.002″ to about 0.005″. Some or all of the wires comprisingthe braid/mesh can also include a radiopaque (i.e. tantalum) coil to aidin visualization.

The device 11 of FIG. 1 may utilize a detachable tip-type system, asdiscussed earlier, since the occlusive device of said figure would beattached to the distal tip of a microcatheter 9 which is deliveredthrough a larger catheter 8. Another embodiment may utilize asolid-lumen pusher instead. This is possible where the device would bedelivered as is, and the microcatheter lumen would not be needed tointroduce subsequent embolic agents. Thus, for example, the occlusivedevice 11 of FIG. 1 may be connected to a pusher rod, which is pushedthrough a delivery catheter or a microcatheter, which is placed withinan aneurysm, the device is subsequently pushed out or the catheter isretracted to expose the device. A thermal, mechanical, or electrolyticdetachment system may be used to detach the center element 16 of thedevice from the pusher rod. Various detachment systems are discussed inU.S. Pat. No. 5,895,385, U.S. Pat. No. 5,108,407, U.S. Pat. No.6,500,149, U.S. Pat. No. 4,346,712, U.S. Pat. No. 8,182,506,US20100268204, US20110301686, US20150289879, all of which are herebyincorporated by reference in their entirety. The pusher rod and catheterare subsequently retracted. Alternatively, the catheter lumen issubsequently used to introduce other embolic agents (such as coils orliquid embolic) proximal to the now-deployed occlusive device. Thus theocclusive device would form a distal barrier to cushion the dome of theaneurysm, and the additional embolic agents would fill the more proximalsection of the aneurysm.

In one embodiment utilizing the device of FIG. 1 but with the devicebeing connected to a pusher rod instead of a microcatheter, a firstcatheter can be used to deploy the occlusive device. A smaller catheterused specifically for embolic agents can then be deployed within thecatheter and can be deployed through the occlusive device to introduceadditional embolic agents (i.e. embolic coils or liquid embolic). Theocclusive device can then be detached. Alternatively, the occlusivedevice can be placed and detached. The catheter, initially used todeliver the occlusive device, can then be used to deliver additionalembolic agents (i.e. coils or liquid embolic). In either case (eitherwhere a separate catheter, or alternatively where the same occlusivedevice catheter is reused), the catheter can be navigated to anotherplace where the catheter sits within the braid to deliver the additionalembolic agents. In one example, the catheter can be placed toward thetop of the occlusive device near the dome of the aneurysm, so theaneurysm and occlusive device would be filled from a top-downperspective. In another example, the catheter can be placed toward thebottom of the occlusive device and the aneurysm and occlusive devicewould be filled from a bottom-up perspective.

The device of the disc-shaped elements of FIGS. 8-12, or thesmaller/larger diameter regions of FIGS. 13-14, or the spiral ribbonshape of FIG. 15 would be connected to a pusher element. Variousthermal, mechanical, or electrolytic detachment systems may be used tosever the device from the pusher element, including the detachmentsystems contemplated in the earlier incorporated by referenceapplications. Similarly, the catheter used to deliver the occlusivedevice may subsequently be used to deliver additional embolic agentssuch as embolic coils or liquid embolic.

FIGS. 16-22 show a pusher detachment system 45 located near a distal endof an elongated pusher device 47. The pusher 47 is advanced through acatheter 8 and its detachment system 47 is actuated to detach anocclusive device 48, such as those devices 48 described in thisspecification. The occlusive device 48 is secured to the pusher via aaxially-movable release wire 38 on the pusher that is, initially,positioned into a cavity of a coupling fixture 40 on a proximal end ofthe device 48, preventing the device 48 from moving sideways off of thedistal end of the pusher 47. The device 48 is prevented from moving offof the release wire 38 by a tether, that is connected to the couplingfixture 40 and to a more proximal portion of the release wire 38 that isexposed from a cut-away region 44 on a distal region of the pusher body36. To aid in flexibility and enhance the connectivity between thepusher body 36 and the coupling fixture 40, a spring 42 is locatedbetween the two.

To actuate the detachment system 45, the release wire 38 is proximallyretracted such that a distal end of the wire 38 moves proximally intothe cut-away region 44 and beyond the proximal point of attachment ofthe tether 46. The tether is connected to the release wire 38 such thatit slides relative to the release wire 38 (e.g., by being tied in aloose knot or via a looped fixture). Hence, the release wire 38 not onlymoves out of the coupling fixture 40, but also retracts to allow thetether 46 to slide completely off with wire 38, leaving the occlusivedevice 48 completely disconnected from the pusher 47. Further, since thespring 42 abuts the coupling fixture 40, it may provide some force orkick to distance the occlusive device 48 from the pusher 47.

FIGS. 17-20 show one possible mechanism to retract the release wire 38of the pusher 47 by breaking a proximal end of the pusher body 36 toexpose a proximal portion of the wire 38, thereby allowing the physicianto proximally pull on the wire 38 and actuate the detachment system 45.As seen in FIG. 17, the proximal end of the pusher body 36 preferablyincludes a weakened area 52 (e.g., one or more holes in the pusher body36) and a visual guide 50 that indicates to a user where a breakage tool54 should be aligned to assist in breaking the pusher body 36.Preferably, the weakened area 52 of the pusher body 36 is strong enoughthat it will generally not break during a procedure without the addedleverage of the tool 54, preventing complications from an unintendedrelease of the occlusive device 48.

The breakage tool 54 preferably has a passage closely sized to thediameter of the proximal end of the pusher body 36, allowing the tool 54to slide over the body 36. The tool 54 preferably includes a narrowregion 56 having a smaller diameter that aligns with the weakened area52, allowing the physician to apply additional force to the weakenedarea 52, breaking both the pusher body 36 and the tool 54 itself, asseen in FIGS. 19 and 20. To aid the physician in properly aligning thenarrow region 56, the pusher body 36 preferably includes a window toallow the user to see and align with the visual guide 50, as seen inFIG. 18. Alternately, the guide may be configured such that the tool 54should be moved immediately adjacent of it or may be configured as atactile detent, eliminating the need for the window.

FIGS. 21-22 show some alternative embodiments to the detachment system45 of FIG. 16. FIG. 21 illustrates a detachment system 53 that issimilar to that of the system 45, but does not utilize a spring 42 toprovide the extra kick to push the coupler 40. FIG. 22 utilizes twowindow cut outs on the coupling fixture 40 and two tethers 46A and 46B.One tether 46A is attached to a distal part of the release wire 38 andthen has a loop around a distal part of the pusher body 36. Anothertether connects to another distal section of the release wire 38 andconnects to a section of the loop around the distal part of the pusherbody 36. In both systems, the knot around the release wire 36 is loose,such that pulling the release wire will release the coupling fixture 40and the implant 48.

The occlusive device embodiments of FIGS. 8-12 and 13-15 may also beconfigured to act similar to the embodiment of FIG. 1. That is, theocclusive device may be pre-loaded at the distal part of a microcatheterwhich is delivered through a larger catheter. The proximal end of theocclusive device, in another embodiment, utilizes an element akin tocenter element 16 of FIG. 1. The center element would bind theconstituent braid wires together. The center element would sit near thedistal end of the microcatheter, and a detachment tip system similar tothe detachable tip systems referenced earlier would be utilized in thesystem. Similar to the embodiment of FIG. 1, the user would position thedevice at the neck of the aneurysm and may optionally deliver embolicagents through the microcatheter (i.e. embolic coils or liquid embolic)through the occlusive device. Once the agents were delivered, the userwould sever the tip of the microcatheter via the earlier contemplateddetachment concepts, and retract the microcatheter.

Intrasaccular braided devices tend to work very well in bifurcationaneurysms in which the delivery catheter can pass relatively straightinto the aneurysm. However, in other aneurysms such as sidewallaneurysms, the delivery catheter position becomes more perpendicular tothe entrance of the neck of the aneurysm, making the deployment ofbraided intrasaccular type device more difficult. When deploying anintrasaccular device at an angle, the relatively stiff nature of thedevice and the pusher it is attached to may cause the catheter tostraighten and the device to deploy at an angle within the aneurysm.

FIGS. 23A-23B show a tensioning system 59 that allows an occlusivedevice 64 to expand in an offset or longitudinally curved configuration,and thereby avoiding the above-mentioned complications. Specifically,the tensioning system 59 includes a tether 58 connected at a distal endand proximal end of a braided occlusion device 64. As the pusher 60pushes the occlusive device out of the catheter 8, the material of thetether 58 is such that it causes the occlusive device 64 to maintaintension on one side of the device 64 during its expansion and allow fullexpansion on the opposite side. This results in the device 64 curving orbending in the direction of the tether 58 during expansion.

A more controlled, bent delivery maximizes the chance that the occlusivedevice 64 adopts its expanded shape to fill the aneurysm when a catheteris unable to access an aneurysm in a relatively straight trajectory. Thetensioning member keeps tension on connected parts of the occlusivedevice, limiting expansion along one side of the device 64 and creatinga curved shape.

The tether 58 may be an elastic polymer, stretched nitinol or stainlesssteel spring coil, nitinol or stainless steel wire, a shape memory wireor ribbon, platinum or tantalum wire or strips. Furthermore, more thanone tether may be used, that is the tethers may be connected in alongitudinal series or may be offset along the vertical dimension of theimplant. In one embodiment, the tether is a nitinol coil or wire and aheat source is connected to the tether in order to change the stiffnessproperties of the tether.

FIGS. 24A and 24B illustrate a braided mesh occlusive device 160 that isbraided such that its expanded mesh shape expands in an offset,non-uniform, angled, or longitudinally curved manner relative thecatheter 8 (or pusher), thereby more optimally expanding into ananeurysm when approached by the catheter 8 at an angle, as seen in FIG.24B. In other words, when the device 160 is expanded, its center axis isoffset from the center axis of the catheter 8 that it expands from.

Such an offset-expanding occlusive device 160 can be created by placinga braided mesh tube or enclosed structure on a mandrel 162 (FIG. 24C)that has a relatively larger diameter cylindrical structure 162A and arelatively smaller diameter cylindrical structure 162B. The smallerdiameter cylindrical structure 162B is fixed at a location that isoffset for the central axis of the larger diameter cylindrical structure162A, thereby imparting the offset shape of the occlusive device 160after being heat-set.

The braided intrasaccular occlusive devices described in thisspecification may be terminated at their proximal end and optionally attheir distal ends via a marker band or other welding techniques, asdescribed elsewhere in this specification. However, it is generallyundesirable for the area of termination to protrude beyond the proximalor distal braided end surface of the occlusive device. For example,protrusion of the proximal end's termination point may extend into theparent artery and may cause unwanted thrombus formation. Additionally,protrusion of the distal end's termination point may cause the dome ofthe aneurysm to rupture.

FIGS. 25A-25D mitigate the above-mentioned complications by reducing theoutward protrusion of the braid termination points when in an expandedconfiguration. Specifically, FIG. 25A illustrates a distally open endedocclusive device 170 that has a proximal braid termination point 170Athat is inwardly recessed when expanded. Similarly, FIG. 25B illustratesan enclosed occlusive device 172 having a distal braid termination point172A and a proximal braid termination point 172B, both of which areinwardly recessed when expanded.

As seen in FIGS. 25C and 25D, a mandrel 174 having a relatively largercylindrical portion 174A and a relatively smaller, adjacent cylindricalportion 174B can be used to create the inwardly recessed braidtermination points. The larger cylindrical portion 174A includes arecess 174C machined into its end and having a diameter such that thesmaller cylindrical portion 174B can be positioned within. The recess ispreferably curved or concave so that it is exposed even when the smallercylindrical portion 174B is within it. The braid of the occlusive deviceis first positioned over both cylindrical portions 174A and 174B, andthen a tube 176 is moved over the portion of the braid on the smallercylindrical portion 174B and pressed against the recess 174C and a clip177 is used to maintain the position of the tube 176. This movementpushes the braid into the recess 174C, allowing the mandrel 174 to beplaced into an oven and heat set to impart the desired recessed shape.While the mandrel 174 is shown with one recessed end 174C and onesmaller cylindrical portion 174A, both ends of the larger cylindricalportion 174A may include these features to create an occlusive device172 with both proximal and distal recessed ends.

FIGS. 31A-31B illustrate another embodiment of a braided occlusivedevice 101 with a fully braided end (or ends) that mitigates thecomplications associate with a protruding proximal or distal end. Inother words, instead of closing the end of a cylindrically braidedstructure via welding or other techniques, one or more of the ends arebraided closed without any termination of the wires at the ends of thedevice 101. In one embodiment, the device 101 comprises a cylindricalbody having at least one end terminating in a plurality of loops thatare interconnected with each other and arranged in a circular patternaround an axis of the device 101, such that the end is free from anyfree ends of the underlying wire of the braid.

The device 101 can be braided on a mandrel 102 (seen in the end-view ofFIG. 31A) that has a desired body shape (e.g., cylindrical) and a domedor convex end (or both ends, if desired). Alternately, the mandrel endsmay have a relatively flat shape, including the pins. The mandrel 102includes a plurality of pins 102A protruding therefrom, which allows auser to wind or braid a wire in a desired braiding pattern around theend of the mandrel 102. After the desired braiding has been performed,the mandrel 102 and device 101 can be heat set to retain the device'sconfiguration on the mandrel 102. The braided end of the device 101 canbe connected to a pusher or catheter via a tether that is tied or loopedthrough a portion of the end, and can be releasable via one of thedetachment mechanisms described elsewhere in this specification.

FIGS. 31C and 31D illustrate two alternate braiding patterns for an endof an occlusive device. FIG. 31C terminates with a plurality ofinterconnected circular loops arranged in an annular shape such that amiddle or axial point of the device is open. FIG. 31D terminates with aplurality of oval, interconnected loops that are arranged over a middleor axial point of the device, such that the middle of the end of thedevice is closed.

FIGS. 26A-26F show different designs for intrasaccular devices, many ofthese designs incorporate multiple folding elements incorporated intothe braiding pattern. The devices shown in these figures may bemanufactured and heat set into a configuration whereby the variouselements fold into each other to create the braided device. Duringdelivery, the device would adopt an elongated, unfolded configurationwhere all the elements lay flat and linearly. Upon release from thedelivery catheter, the braid would then adopt its folded configurationas the various layers sequentially push into the previously deployedlayers. This folding effect is particularly helpful for occlusivepurposes since the braids will be packed and increase the occlusivedensity of the mesh. Alternatively, the elongated, delivery shape of thedevice would also utilize the same folded shape—just stretched andelongated compared to the final, deployed shape. In one example, thedistal end of the braid can utilize a longer stem, thus the stem wouldpush and expand against the dome of the aneurysm providing a soft distalcap against which the rest of the braid will contact and fill out therest of the aneurysm.

FIG. 27A illustrates a sealing device 69 that can be used with anocclusive device 66, such as those described in this specification. Thesealing device 69 includes a concave sealing portion 70 that isconnected to the occlusive device 66 by a connecting member 68. Asealing device 69 can be delivered at the distal end of the deviceand/or at the proximal end of the device 66. If placed at the distal endof the device 66, the sealing device 69 would contact the dome of theaneurysm and provide a distal scaffold against which the rest of themesh occlusive device 66 can fill the rest of the aneurysm. If placed atthe proximal end of the device, the sealing device 69 would seal theneck of the aneurysm and prevent the occlusive device from sittingoutside of the aneurysm. Additionally, if subsequent embolic deviceswere placed after the intrasaccular device (i.e. embolic coils or liquidembolic), the proximal sealing device 69 would provide a catch typeelement to prevent the embolic from falling out of the aneurysm. In oneexample, the sealing element is comprised of an umbrella-shaped seriesof wires which optionally utilize a membrane over the wires. If thesealing device 69 is connected to the occlusive device 66 within theaneurysm, the connecting member 68 has a plurality of hooks or othermechanical engagement members that can engage the occlusive device 66during subsequent delivery. However, the sealing device 69 can also beconnected to the occlusive device 66 prior to delivery, and thereforeconnecting member 68 can also include adhesives, welding, or otherengagement mechanisms.

FIG. 27B illustrates a proximal and distal sealing device 69 used in asimilar arrangement with an occlusive device 72 that is formed intothree folded layers of braided mesh. The connecting member 68 isconnected to an inner filling member 71 and located inside of the layersof the occlusive device 72, augmenting the occlusion of the device. FIG.27C illustrates a similar arrangement to that of FIG. 27B, exceptwithout the use of the inner filling member 71. The filling structure 17may take the form of wires, hypotubes, or sheet-cut structures. Thefilling structure 17 can be shaped in a number of ways, such as a linearshape, wave-like shape, sinusoidal shape, and/or coiled-shape in orderto promote occlusion of the target area. In one example, the fillingstructure may be made of nitinol wires from about 0.002″-0.005″ indiameter. Other examples may utilize shape-setting polymers,cobalt-chromium, and spring-tempered stainless steel. In one example,each wire includes a tantalum coil for imaging and the tantalum coilwraps around the wire and extends either throughout the wire, orthroughout a sufficient length of the wire to enable visualization ofthe device during the treatment procedure.

FIG. 27d illustrates the wire understructure of the sealing device 69without its mesh or membrane covering as it is delivered from acatheter. During delivery, the sealing device 69 would adopt a linear,elongated shape when collapsed within a catheter, and then would adoptan expanded, umbrella shape upon release.

This sealing concept can be useful in other embodiments, for example aneck bridge element may utilize a proximal sealing device which blocksthe neck of the aneurysm and other embolic material (such as coils orliquid embolic) may then be placed within the aneurysm and be cradled bythe sealing device. In FIGS. 27E and 27F, the occlusive devices 75, 77comprise a wire scaffold 78—in FIG. 27E the wires form a spherical shapeand the device is meant to substantially fill the aneurysm, and in FIG.27F the wires extend to form a partial sphere and the device is notmeant to substantially fill the aneurysm. The proximal and distal endsof the wire scaffold 78 can utilize a sealing member 76, where all thewires are grouped together by the sealing member. The proximal end ofthe device can utilize a mesh or membrane, for instance, to seal theneck of the aneurysm. The neck seal may be delivered at the distal endof a pusher where the neck seal is detached, and then a catheter issubsequently introduced into the neck seal to deliver additional embolicagents such as coil and/or liquid embolic. Alternatively, the neck sealmay be delivered at the distal end of an open lumen pusher (analogous toa microcatheter), the neck seal is placed within the target site, andthe open lumen of the pusher is subsequently used to deliver additionalembolic agents. The pusher is subsequently detached. The mesh/membranecan also be placed within the scaffold, as indicated by element 74 ofFIG. 27E. Placing the mesh or membrane in such a manner will, inessence, create an occlusive region spanning from the neck of theaneurysm to the top of the membrane. Embolic (i.e. coil or liquidembolic) which is subsequently introduced would be captured within theregion defined by the membrane. Different variations of this concept caninvolve a wire form scaffold, but where the mesh/membrane is placed allaround the scaffold, solely around the middle of the scaffold, or solelyat the distal end of the scaffold. The neck bridge would assume acollapsed configuration when housed within a delivery catheter and wouldadopt its expanded shape (see FIGS. 27E-27F) upon delivery, oncereleased from the catheter. The mesh/membrane material used may becomprised of a polymer or a metallic material. The mesh/membrane can beaffixed to the wire scaffold via adhesive, stitching, heat treatment, orother means. Though a wire scaffold is described, different variationsare possible. For example, the scaffold may primarily utilize wires tocreate the scaffold—however, link elements (think of a jewelry pendantor chain link) may be selectively incorporated along the length of thewires to augment flexibility. Alternatively, the scaffold may becomprised of a laser cut sheet.

FIG. 30 shows a mandrel and winding technique which can be used to winda braid to create an occlusive device. This design utilizes gravity fortension and to wind the braid. The wires 96 comprising a braid areinitially placed on mandrel 94. The top of the mandrel can have notchesor grooves to accommodate the wires, or the wires can be placed at thetop of the mandrel and affixed via tape or other means to keep tensionon the wires initially. Weights 98 are placed at the bottom of the wiresand a braid ring 100 is also utilized. The braid ring has notches toaccommodate the wires and the braid ring is also selectively movable upand down the mandrel, but can be locked into place as well. The braidring is used to control the angle of the wire braid, keeping the braidring higher will result in a smaller braid angle and a denser braidconfiguration, while keeping the braid ring lower will result in alarger braid angle and a looser braid configuration. The user will lowerthe braid ring to keep a consistent tension and consistent braid angleon the braid as they wind the wires over the mandrel, the user willmanually wind the various wires above and below each other to create thebraid. To keep a consistent braid angle, the braid ring will be loweredas the user winds each incremental section of the braid. The device canbe heat set after being wound to reinforce the shape.

Parts of the description have discussed the use of a braider to create abraided device, typically these braiders utilize a mandrel which moveslongitudinally and a series of bobbins mounted within a carrier frame,where the bobbins rotate in various configurations within the carrierframe. The rotation of the bobbins and carriers coupled with thelongitudinal movement of the mandrel enable the braiding of the deviceto occur. In another embodiment, a rotational braider may be used—thatis instead of the bobbins housed within the braider moving around or thecarriers moving around, the braider itself may also have freedom torotate. FIG. 32A illustrates the typical shape of a wire braidintersection. Each line represents a wire, thus the cross points of fourwires create the shapes shown—for ease of reference, we will refer tothis 4-wire crossing point as a cell. Since the braid angle of FIG. 32Ais consistent, a diamond-type cell shape is typically generated duringthe typical braiding process. Adding rotation to the braider itself, inaddition to the rotation of the bobbins and carriers would allowadditional possibilities. Adding rotation to the braider would shift thewinding angle as the braider is winding over the mandrel, allowing formore off-kilter shapes such as the ones shown in FIGS. 32B-32C, insteadof a diamond-type shape, the angles shift to more of a parallelogramtype configuration. Rotating the frame clockwise will produce one shape,rotating the frame counterclockwise will produce another shape. This canbe useful where, in selective regions of the manufactured braided device(i.e. occlusive device) you want areas with different flexibility—havingthe more stretched braid section shape of FIGS. 32B-32C will introduce adifferent stiffness profile than the shape of FIG. 32A. For example,perhaps the manufacturer wishes to create a braided device with ageneral stiffness throughout most of the device, but a differencestiffness profile in the middle. When the middle section of the braid iswound, the user can rotate the carrier frame to create the type of cellshapes shown in FIGS. 31B-31C, which will thus alternate the stiffnessprofile of the device within that particular region. Such a process canbe automated, so for instance the braiding process is typicallyautomated, so the carrier frame rotation capability can also beautomated and can thought of as another variable in the windingoperation. Other variables include the longitudinal speed of themandrel, the rotational speed of the carriers and bobbins as they wrapthe wires around the mandrel, the angles of the braids, etc.

Other embodiments may utilize a distal filling structure and a proximalneck-bridge structure. The filling structure may take the form of wires,hypotubes, or sheet-cut structures. The filling structure can be shapedin a number of ways, such as a linear shape, wave-like shape, sinusoidalshape, and/or coiled-shape in order to promote occlusion of the targetarea. In one example, the filling structure may be made of nitinol wiresfrom about 0.002″-0.005″ in diameter. Other examples may utilizeshape-setting polymers, cobalt-chromium, and spring-tempered stainlesssteel. In one example, each wire includes a tantalum coil for imagingand the tantalum coil wraps around the wire and extends eitherthroughout the wire, or throughout a sufficient length of the wire toenable visualization of the device during the treatment procedure. Theneck bridge may comprise a mesh braid element which sits at the neck ofthe aneurysm or just within the aneurysm and would prevent the fillingstructures from falling out of the aneurysm. Alternatively, theneck-bridge may comprise a structure comprising a plurality ofdisc-shaped elements where one disc sits inside the aneurysm and othersits external to the aneurysm. The neck bridge may be a metallic braid(i.e. nitinol, stainless steel, cobalt-chromium) or polymeric.

FIG. 35 shows a distal wire filling structures 110 and proximal meshneck-bridge structure 112A used to occlude an aneurysm. The device isdelivered from a catheter 8. In one example, the distal fillingstructures 110 and proximal mesh/neck-bridge structure 112A areconnected and the whole system may be pushed via a core wire-basedpushing system where a detachment system is incorporated at the end ofthe core wire and proximal of the mesh/neck-bridge to detach the device.Any mechanical, thermal, or electrolytic detachment system may be used,including the other detachment concepts disclosed in this specification.

FIG. 36 illustrates an embodiment similar to that of FIG. 34, excepthaving a dual-disc neck bridge structure 112B. In this example, the neckbridge 112B may comprise a plurality of disc-shaped elements where onedisc sits inside the aneurysm and the other disc sits outside theaneurysm.

In one embodiment, the filling structures 110 are affixed to a distalportion of the neck bridge 112A/112B. When delivered, the whole systemwould be collapsed within the catheter 8 with the filling structures 110sitting distal of the neck bridge. In another embodiment, the neckbridge structure 112A/112B would be preplaced at the distal end of thecatheter 8, and sit outside the catheter 8. In one embodiment, thecatheter 8 extends through the neck bridge 112A/112B to provide a lumenfor delivery of additional embolic agents through the neck bridge112A/112B and into the aneurysm 14.

In another embodiment, the neck-bridge structure 112B shown in FIG. 34may utilize one or more lumens and the filling structures are deliveredthrough the one of more lumens, through the neck bridge 112B, and intothe aneurysm 14. The filling structures would be delivered through thecatheter and through the neck bridge, and would be placed through theneck bridge after the neck bridge is deployed.

In one embodiment, the filling structures 110 are affixed to the neckbridge 112A/112B which is proximal to the filling strictures 110. Thefilling structures 110 and attached neck bridge are pushed through thecatheter 8 via a proximal pushing system. A detachment system(electrolytic, thermal, mechanical, other detachment systems describedin the specification or previously incorporated by reference) link thepusher to the neck bridge. The pusher is used to push the neck bridgeand filling structures out of the catheter, and the detachment system isthen used to detach the system from the pusher, and the pusher is thenwithdrawn. FIG. 37 shows a cross sectional view of such an arrangementin which the filling structures 110 are affixed to the distal portion ofthe neck bridge (not shown), and the entire device is delivered througha catheter 8. Three filling structures are used. The filling structures110 include a wire 111 surrounded by a radiopaque coil 116 to aid invisualization. The radiopaque coil 116, in one example, comprisestantalum or tungsten and has a 0.001″ filar, which is a diameter that isslightly larger than the wire 111 since the coil 116 sits around thewire 111. The neck bridge 112A/112B sits proximally of the fillingstructures. A proximal pusher, such as a core wire pusher, is connectedto the neck bridge 112A/112B. A detachment system, utilizing thermal,mechanical, or electrolytic means can separate the pusher from the neckbridge 112A/112B. Any of the detachment systems discussed in thespecification, and any of the systems incorporated by reference can alsobe used.

FIGS. 38 and 39 show another embodiment in which a distal neck bridgestructure 112B (or alternately 112A) includes an internal channel 124connected to the catheter 8 so that a continuous lumen is presentthrough the neck bridge 112B. The neck bridge 112B may sit distal of thecatheter 9. In another example, a portion of the neck bridge 112B wouldsit distal of the catheter 8 and a portion sits within the catheter 8and a detachable pusher element is used to push the neck bridge 112B outof the catheter 8 when the catheter 8 is placed in an appropriatelocation (i.e. near the aneurysm or treatment site). Alternatively, thecatheter 8 can be retracted to expose the entire neck bridge 112B. Sincethe neck bridge 112B contains a lumen, when the neck bridge isappropriately placed, the lumen can be used as a conduit to push embolicagents (such as embolic coils) through the neck bridge 112B into thetreatment site (e.g., aneurysm). The neck bridge 112B would prevent theembolic coils from falling out of the treatment site and migratingelsewhere. The neck bridge may be pushed out of the catheter 8 so thatthe catheter 8 can be withdrawn, or alternatively the catheter 8 caninclude a detachment system (thermal, mechanical, electrolytical, otherdetachment described herein, or other detachment systems incorporated byreference within the specification) to detach the catheter from the neckbridge.

U.S. Pub. No. 20150173772 discloses an embolic coil system utilizingdetachable elements along the length of the coil to create a variabledetachment system where selective lengths of the coil can be deployedwithin a target treatment site, and is hereby incorporated by referencein its entirety. One embodiment, shown in FIGS. 38-39, can utilize avariable detachment coil system along with the neck bridge concept. Thevariable detachment system utilizes a contact element on the catheter tointeract with the links in between the embolic coil segments, the linksinclude a degradable element which degrades when the catheter contactelement electrically interacts with the coil links to sever a segment ofthe coil. Element 124 represents the inner lumen which spans theinterior of the neck bridge 112 in FIG. 39, this lumen is connected tocapsule 126 which comprises a degradable linkage which severs the neckbridge from the catheter delivery system. The embolic coils 120 whichare pushed through the catheter (see FIG. 38) include links 122, thelinks electrically interact with capsule element 128 (see FIG. 40) todetach appropriate segments of the embolic coil within the vasculature.Catheter 8 provides the delivery platform for both the neck bridge(connected distally to the catheter) and for the embolic coils which aredelivered through the catheter. The inner lumen and attached neck bridgeare separable from the catheter via degradable capsule 126. The capsulecan use detachment means, as discussed earlier, to detach the neckbridge 112 and inner lumen 124 spanning the interior of the neck bridge,from the catheter. Several wires 130 are used to convey current tocapsules 126 and 128, a voltage source (i.e. battery) sits at theproximal end of the system and conveys current between the battery andthe capsules. Inner lumen 24 may comprise a number materials includingpolymer, metallic, metallic mesh.

Previous embodiments discussed utilizing a neck bridge which either sitswithin or at the neck of an aneurysm (FIG. 35) or which has a portionsitting inside the aneurysm and another sitting outside (FIG. 36).Another embodiment would utilize a floating neck bridge, the neck bridgewould be deployed within the aneurysm and as either the fillingstructures or embolic coils were deployed into the aneurysm, theseembolic materials would occupy the internal space of the aneurysm andeventually push the neck bridge down so it seals the neck of theaneurysm. In one example, catheter 8 displayed in FIGS. 35-40 is amicrocatheter with a diameter of 0.017″-0.021″.

Yet another embodiment of an occlusive device 143 is shown in FIG. 41 ina compressed, elongated state during delivery in a catheter 8 and inFIG. 42 in an expanded configuration emerging from the catheter 8. Thedevice 143 includes a number of structural loops or struts 138 connectedto a distal occlusive portion 140. The distal occlusive portion 140,when used in an aneurysm, creates a dome or concave occluding region inthe aneurysm while the struts 138 help expand the occlusive portion 140and fill out the area underneath the occlusive portion 140.

Connecting structures 142 are fixed to the to the distal contact portion140 (e.g., via adhesive or welding) and are fixed to the struts 138(e.g., via a loop through which the struts 138 pass through), therebyconnecting the struts 138 to the distal occlusive portion 140. Thestruts can be comprised of a metal or polymer, such as nitinol wire or ahypotube—although radiopaque items can also be used to aid in imaging.The distal occlusive portion 140 can either have a pre-set curved shape,or it can comprise a malleable, thin material so to conform the shape ofthe aneurysm. In one example, distal occlusive portion 140 is a thinfilm polymer (e.g., PTFE, ePTFE, polyethylene) or metallic (e.g.,nitinol, stainless steel) material. The struts 138 help control theexpansion of the distal contact portion and help ensure the device 143deploys gradually.

A proximal end of the struts 138 are connected to a cylindricalcollector band 136, for example by passing through apertures in thecollector band 136. A coil 134, in one example stainless steel, isconnected to a proximal end of the collector band 136 and to a distalend of a proximal band 132 on the pusher 131, thereby helping to propelthe struts, as well as distal occlusive portion 140, open. The coil 134adopts a compressed shape when the device 143 is within a catheter 8,since the struts 138 also adopt a compressed, elongated shape. The coil134 thus has stored energy and as the device 143 is delivered and thestruts 138 start to open up, the coil 134 discharges this stored energywhich helps to further expand the struts as well as the attached distalcontact portion 140.

The pusher 131 can comprise a core wire or hypotube system and allowsthe user to manipulate the device 143 through the catheter 8 and throughthe vasculature. A detachment system can be included at a locationdistal of the pusher. In one example, coil 134 is also part of thedetachment system and a severable tether is located within the lumen ofthe coil 134. Wires can connect on either end of the coil and thesewires connect to a voltage source such as a battery at the proximal endof the system, allowing the user to initiate a detachment sequence (i.e.by pushing a button) to heat the coil and sever the tether to detach thedevice from the pusher. The detachment system may be flush or distal tothe coil 134 so that the coil 134 does not get propelled into thevasculature. In one example, the detachment system utilizes a tetherspanning the collector band 136 through coil 134, and the coil is firmlyconnected to element 132. Thus when the detachment sequence is initiatedand the device is deployed, the tether will sever but the coil willremain attached to the pusher since the proximal end of the pusher isattached to proximal band 132.

A tensioning element 141 can also be used, connecting the distalocclusive portion 140 to struts 138. The tensioning element 141 may be athin wire or tether and would help control the expansion of distalportion 140 and struts 138 upon delivery so the opening is slowed orless abrupt.

The struts 138, in one example, are heat treated to have a shape memoryopened shape as shown in FIG. 40, this shape memory would make thestruts 138 open quickly to adopt their shape memorized open shape, andthe tether would help control the opening of the device during delivery.The tensioning element 141, alternatively, may span the area betweendistal occlusive portion 140 and the pusher 131, or proximally at thebase of the struts 138, band 136, coil 134, element 132, or pusher 131.Affixing the proximal end of the tether to a non-strut element wouldhave the advantage of fixing it to an element that does not expand,resulting in a very controlled deployment. Affixing the proximal end ofthe tether to a strut 138 would still constrain the expansion, but notas much, since the proximal end is secured to something which expands ondeployment. The location of the proximal end of the tether may becustomized based on whether the user wants or more or less controlledexpansion of the device upon deployment—materials used in the device,and size of the device would be important variables in play.

FIGS. 43-45 illustrate an occlusive device 145 having a concave topocclusive element 144A and a concave bottom occlusive element 144B to,respectively, expand against the dome and the neck of an aneurysm. Thetop and bottom elements 144A, 144B can be comprised of a variety ofcomponents, including metallic mesh, metallic sheets, and polymer. Acoil 146 connects to the top and bottom occlusive elements 144A, 144B,connecting both elements 144A, 144B while allowing for variation indistance to accommodate different aneurysm sizes. The top element 114Ais deployed first into the aneurysm and the bottom element 1148 is thelast element out of the catheter. As seen in FIGS. 44 and 45, the device145 may optionally include a frame 148 that expands within the top andbottom elements 144A, 144B. The frame 148 has a plurality of loops thatexpand radially across the openings of the concave opening of theelements 144A, 144B, acting as a scaffold for the opening and closing ofthe top and bottom elements, while also providing for a more controlledexpansion and contraction of the device. FIG. 45 shows the device 145 ina collapsed configuration which it would adopt during delivery via acatheter. The frame elements 148, when collapsed, would sit over aportion of the coil (think of an umbrella frame when contracted comparedto when expanded); when expanded the frame elements would sit flush orwithin the top and bottom elements, respectively.

Other embodiments may utilize the distal filling structure 110 describedearlier and shown in FIGS. 35-36, but utilized with the device shown inFIG. 1 which includes a retention portion 10 and holding portion 12.

Previous discussion discussed various mandrels and winding techniquesused to create an occlusive device. Another embodiment utilizes aremovable mandrel, where fracturing, chemical dissolution, or othertechniques can be used to remove the mandrel after the manufactureddevice is braided over the mandrel. The manufactured device may be anumber of devices, such as braided therapeutic devices, includingocclusive devices. Conventional braiding technologies utilize braiding adevice over a mandrel, heat setting the device over the mandrel, andsubsequently removing the mandrel. The mandrel can optionally include anumber of pins around which the device is braided. Where anon-cylindrical, tapered occlusive device is created (i.e. one where theends are smaller than the center), removing the mandrel can be difficultdue to the tapered shape of the mandrel and occlusive device. One methodof solving this issue is to use a mandrel which can be removed viamechanical means (i.e. fracturing) or chemical means (i.e. chemicaldissolution) to remove the mandrel and leave the braided device.

In one embodiment, the mandrel is comprised of ceramic or glass. Ceramicand glass are both highly brittle, therefore the mandrels can bemechanically fractured by a hammer after the device is formed to removethe mandrel. If a glass mandrel is used, the glass can be coated with asilicone or latex material to prevent the device wound over the mandrelfrom slipping. In another embodiment, an aluminum mandrel is used and aconcentrated sodium hydroxide solution is used to dissolve the mandrel.A concentrated (i.e. 1-10 M) sodium hydroxide solution may be used witha high temperature (i.e. 100-150 degrees F.) along with fluidconviction. The aluminum mandrel will slowly dissolve, but the techniquewill not dissolve other materials such as nitinol that might be used towind the interventional device. Thus the mandrel will disappear and thedevice will remain. In another embodiment, the mandrel is sand cast. Asand cast mandrel is removable via a fluid jet and will simply leavesand once the formed mandrel breaks up. In one example, the mandrel hasan aluminum core is used and a sand cast is built over the top of thealuminum core. Another embodiment may utilize a removable mandrelcomprising a wire-form structure, similar to the braided structurecreated over the mandrel. Thus the mandrel comprises a first braid, anda second braided interventional device is wound over the braidedmandrel. The braided mandrel can be easily compressed to remove thebraided interventional device. The braided mandrel should comprise anywire structure that balances strength and compressibility and canwithstand the high heat-set setting temperature, examples include 316stainless steel or 321 stainless steel. Another embodiment utilizes amandrel comprising a first layer (i.e. a typical metallic mandrel) and asecond layer, where the second layer comprises any of the removablemandrel elements described herein, in order to create a dual ormultiple-layered braided interventional device. The user winds the firstlayer of the device over the base mandrel. A second mandrel layer, whichis removable, is then placed over the first mandrel layer and firstbraided layer of the interventional device. The second layer of theinterventional device is then wound over the second (removable) mandrellayer. The removable mandrel section is then removed, leaving the firstmandrel and the multiple layered interventional device. Though thisprocess was described to create a two or dual-layer device, additionalremovable mandrels may be added to create a three, four, five, etc.layer braided interventional device.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. An occlusive device for medical treatment of a lumen, comprising: a holding portion formed from a plurality of wires braided into a cylindrical shape with a closed proximal end; the closed proximal end having a first aperture; a catheter having a distal end that is detachably connected to the holding portion; the catheter having a passage extending to the distal end of the catheter and being aligned with the first aperture of the holding portion; wherein embolic material within the passage of the catheter is advanceable through the passage, through the first aperture, and within the cylindrical shape of the holding portion.
 2. The occlusive device of claim 1, further comprising a retention portion having a plurality of loops located within the cylindrical shape of the holding portion and further having a second aperture aligned with the first aperture.
 3. The occlusive device of claim 2, further comprising a center element having a plurality of loop apertures located around a periphery of the center element and through which wire forming the plurality of loops pass through; the center element further comprising a third aperture aligned with the second aperture and the first aperture.
 4. The occlusive device of claim 2, wherein the plurality of loops of the retention portion further comprise a first plurality of loops located against the closed proximal end of the holding portion, and a second plurality of loops located distally of the first plurality of loops.
 5. The occlusive device of claim 1, wherein the closed proximal end of the holding portion is formed from a plurality of triangular flaps that are connected together at their ends.
 6. The occlusive device of claim 1, wherein the closed proximal end of the holding portion terminates with a cylindrical marker band having a passage therethrough that is aligned with the first aperture of the closed proximal end of the holding portion.
 7. The occlusive device of claim 1, wherein the closed proximal end further comprises a braided, enclosed end having a plurality of interconnected loops circularly arranged around an axis of the occlusive device such that the closed proximal end is free from any free ands of the plurality of wires.
 8. The occlusive device of claim 1, wherein the holding portion is detachable from the distal end of the catheter.
 9. The occlusive device of claim 1, wherein the distal end of the catheter further comprises a sacrificial material that is further connected to the holding portion, and wherein the distal end of the catheter further comprises a heater disposed near the sacrificial material so as to melt the sacrificial material and detach the holding portion from the catheter.
 10. An occlusive device for medical treatment of a lumen, comprising: a three dimensional structure formed from a plurality of braided wires and being selectively detachable from a delivery device; wherein the three dimensional structure has a linear compressed shape within the delivery device, and wherein the three dimensional structure has an expanded state that expands away from an axis of a distal end of the delivery device in a longitudinally angled and an axially offset manner.
 11. The occlusive device of claim 10, further comprising a tether connected along a side of the three dimensional structure, between a distal end and a proximal end of the three dimensional structure, so as to cause the three dimensional structure to curve in a direction of the tether.
 12. The occlusive device of claim 10, further comprising a plurality of tethers longitudinally aligned in series between a distal end and a proximal end of the three dimensional structure.
 13. The occlusive device of claim 10, further comprising a first tether connected along a first side of the three dimensional structure and a second tether connected along a second side of a three dimensional structure, so as to cause the three dimensional structure to curve away from an axis of the occlusive device.
 14. The occlusive device of claim 11, wherein the tether comprises an elastic polymer, stretched nitinol or stainless steel spring coil, nitinol or stainless steel wire, a shape memory wire or ribbon, or platinum or tantalum wire.
 15. The occlusive device of claim 10, wherein the expanded state of the three dimensional structure is heat set to expand in a longitudinally angled and axially offset manner from the axis of the distal end of the delivery device.
 16. The occlusive device of claim 10, wherein the three dimensional structure is created by placing a braided mesh structure over a mandrel having a first cylindrical portion and a second cylindrical portion that is smaller than the first cylindrical portion and attached to an end of the first cylindrical portion, wherein the second cylindrical portion is offset from a middle of the first cylindrical portion, and wherein the braided mesh structure and mandrel are heated to impart the shape of the mandrel on the braided mesh structure.
 17. The occlusive device of claim 10, wherein the catheter further comprises a heating coil configured to cause detachment of the three dimensional structure from the catheter.
 18. An implant delivery system comprising: an implant; a delivery tube with a continuous lumen therein, the implant operatively connected to a distal section of the delivery tube; a heater and a sacrificial layer extending around part of the circumference of a distal section of the delivery tube; where the heater melts the sacrificial layer to detach the implant from the delivery tube.
 19. The implant delivery system of claim 18, wherein the sacrificial layer sits between the heater and a cover piece. 